Abdullah quickly assumes Saudi throne after half brother's death

RIYADH, Saudi Arabia -- King Abdullah quickly assumed the Saudi throne Monday after the death of his long-ailing half brother, giving a smooth transition to the leadership of this key U.S. ally and oil giant already grappling with extremists and debating the need for reform.

After a decade as de facto ruler and the prime mover of recent reforms, the popular 81-year-old Abdullah is expected to seek to consolidate his power by bringing more allies into government and perhaps open the door for younger, more modern princes to play a role.

Some people expect him to face behind-the-scenes competition from a clique of half brothers who hold their own powerful posts and have close ties with Saudi Arabia's conservative Muslim clerics.